In a semiconductor manufacturing process, a defect, such as a scratch or a foreign substance, on a wafer affects the yield of products. Accordingly, to detect a defect on a wafer, feed it back to the semiconductor manufacturing process, and manage the detected defect is important in managing the yield. What is used to detect such a defect is a so-called inspection device.
In an inspection device, a threshold (or a threshold plane) used when detecting a defect is placed on a defect feature space. Furthermore, by classifying the type of the detected defect, more accurate yield management can be achieved. As a prior art relating to the setting of a threshold for detecting a defect, PTL 1 is cited.